1. Field of the Invention
The present invention relates to a safety belt arrangement, especially for motor vehicles, that includes a lap belt as an integral portion of the belt system. One end of the lap belt is attached to an element that is connected to the vehicle. The other end of the lap belt is provided with a belt buckle part. An anchoring member is provided as a carrier for the other belt buckle part. The ends of the lap belt on the one hand, as well as the anchoring member on the other hand, are connected with a tensioning mechanism that operates in opposite directions.
2. Description of the Prior Art
The present invention can be used for all types of safety belts. For example, the present invention can be used with three-point safety belts where the belt extends as a shoulder belt from a belt reeling mechanism, which is generally mounted on the B- or C-column of the vehicle (for which as generally known such letter designations are used to refer to the front or windshield column as the A-column; the middle column referred to as the B-column generally laterally adjoining the backrest of the front seat; and the rear column referred to as the C-column in the rear quarter panel or trunk region of the vehicle), to a belt buckle part (generally a buckle tongue), and from there as a lap belt to a point of securement on a part of the vehicle. The present invention can also be used with a lap belt where the belt extends from the point of securement over the lap of the person who is strapped in to another point of securement that is next to the person and is in the form of a belt buckle lock having an anchoring member. These two types of belts are frequently combined with one another, especially on the rear seats of automobiles, with the persons sitting on the outsides each being strapped in via three-point belts, and with the person sitting between them in the middle being strapped in by a simple lap belt.
Safety belt arrangements for restraining a person generally have the problem that in the event of an accident, for example a collision, the strapped-in persons have not only their upper body thrown forward, but in particular can also slide forward beneath the lap belt, as a result of which the lap belt assumes an unfavorable position with regard to the geometry of the belt, cutting into the abdomen region of the body of a person. This applies in particular, of course, for persons secured merely by a simple lap belt.
U.S. Pat. No. 4,015,806-Tisell et al dated Apr. 5, 1977 corresponding to German Offenlegungsschrift No. 25 43 068 Karlstedt et al dated Apr. 8, 1976 proposes for the front seat of automobiles that the lap belt be essentially simultaneously tensioned at both ends, with the two lower points of securement of the lap belt being connected via lines with a pyrotechnical drive mechanism that is disposed below the seat and has two pistons that are movable in opposite directions; in the event that the mechanism is triggered, these pistons are driven apart in opposite directions, thus tensioning the lap belt. The lines that lead from the lap belt to the piston are preferably guided via rollers. However, such an approach cannot be used with current safety belt systems.
It is therefore one object of the present invention, for a safety belt arrangement, to provide a direct tensioning of the lap belt independent of the tensioning of the shoulder belt.
A further problem encountered during tensioning of lap belts is that the anchoring points for the lap belt connection on the one hand, as well as the anchoring member as the belt buckle carrier and hence constituent of the portion that extends around the abdomen region of the strapped-in person, and hence the geometric course of the lap belt, are predetermined by the vehicle. This means that, for example, for a small person, the lap belt on both sides, or at least on one side, is at a distance from the body, so that even if the lap belt is tensioned, there is still enough space for the person to slide through beneath the belt. In addition, the lap belts extend rearwardly to the points of securement at a spacial acute angle relative to the securement plane, so that the belts do not optimally extend around the strapped-in person. Moreover, as a result of the acute angle high forces result at the points of securement, so that at this location a high effort is extracted to secure the strapped-in person. This problem attains particular weight with regard to the back seats of automobiles, since in particular the back seat can be occupied by up to three persons, so that here the points of anchoring could be placed particularly unfavorably.
It is therefore a further object of the present invention to improve the geometry of the course of the lap belt at the same time that the latter is tensioned, and to conform the belt geometry to all seat configurations.